1. Field of the Invention
The present invention relates to a light emitting device, and more particularly relates to a surface mount type of light emitting device that is compact and lightweight.
2. Background Information
Light emitting devices that are compact, have good sensitivity, and have light emitting elements with high brightness and high output have been developed and put to use in various fields in recent years. Because of their compact size, low power consumption, light weight, and other advantages, such light emitting devices have been used, for example, for light sources in portable telephones and liquid crystal backlights, as light sources for various kinds of meter, and as various kinds of read-out sensor.
A light source used for a backlight, for example, needs to have a thin construction so that the device in which it is used can be made more compact and lightweight. Therefore, the light emitting device used as the light source must itself be compact in size, and to this end a variety of light emitting devices have been developed in a configuration called a side view type.
A side view type of light emitting device is generally configured such that an opening for releasing light is formed in a side face of a package, a light emitting diode chip is mounted on the bottom face of the package, and part of a lead frame is taken as an external terminal from the inside of the package to the outside. Such side view type of light emitting device is usually formed by molding a resin using a metal mold in which lead frames are sandwiched.
However, as the size of these side view type of light emitting devices have decreased, their walls have become extremely thin, so that they sometimes cannot withstand the parting resistance with the mold when the molded package is removed from the mold, causing the thin wall portions to tear and lose their shape.
Accordingly, it is has been proposed that parting can be facilitated by using ejector pins to eject specific regions on the top face or rear face sides of the upper and lower molds (for example, JP-H07-214600-A).
It has also been proposed that removal of a molded package from a mold can be facilitated by forming relatively gentle tapers at two stages on the top face of a light emitting diode chip (for example, JP-2000-77721-A).
However, when ejector pins are used as discussed above, because holes are made in the mold for inserting the ejector pins, and the injector pins are inserted through these holes, tiny gaps are produced between the ejector pins and the holes. Consequently, the problem is that the package material finds its way into these gaps and results in flash when the package is removed from the mold. If flash is produced on the package surface, depending on how the package is to be used, there may be difficulty in positioning with other members, and misalignment may occur, which can have a serious effect on the design of a system in which this light emitting device is used.